A kind of method for preparing ammonium carbonate solution from aqueous solution containing ammonia

Abstract

The invention particularly relates to a method for preparing a high-concentration ammonium carbonate solution from a low-concentration ammonia-containing aqueous solution. The method comprises the following steps: 1) regulating a pH value of the ammonia-containing aqueous solution which serves as a raw material to be 11.00-13.50, and blowing ammonia out of the ammonia-containing aqueous solution to obtain ammonia gas; 2) by taking the ammonium carbonate solution with the pH value of 9.50-10.00 as an absorption solution, alternatively introducing CO2 gas which serves as raw material gas and the ammonia gas prepared in the step 1) into the absorption solution; or alternatively feeding the absorption solution into a carbonization device and an ammonium absorption device, introducing the CO2 gas which serves as the raw material gas into the carbonization device, and introducing the ammonium gas prepared in the step 1) into the ammonium absorption device; taking the absorption solution product obtained in the steps as the prepared ammonium carbonate solution. The process conditions are controlled, so that the absorption rate of ammonium and CO2 in the ammonium carbonate production process can be improved, and moreover, the process is simple, the investment cost is low, a rectification or steam stripping process is not required, the energy consumption is low, and the requirement of CO2 content in the CO2 gas which serves as the raw material gas is relatively low.

Description

technical field [0001] The invention relates to a method for preparing an ammonium carbonate solution from an ammonia-containing aqueous solution, in particular to a method for preparing a high-concentration ammonium carbonate solution from an aqueous solution containing low-concentration ammonia. Background technique [0002] Invention patent CN201010177402.0 proposes a process of coupling calcium salt method and electrodialysis to produce lactic acid. This process can overcome the defect of calcium sulfate waste residue produced in the production of lactic acid in the existing production technology, and can be compared with the calcium salt method currently used in industrial production of lactic acid. Fermentation is directly connected, and the closed loop of materials is realized. This method still uses CaCO in the lactic acid fermentation stage 3 Adjust the pH of the fermentation broth; then, use ammonium carbonate as a precipitant to replace the fermentation broth con...

AI Technical Summary

Problems solved by technology

[0011] This method consumes a lot of steam, about 120-250kg / m 3 Raw material, steam stripping is highly corrosive to equipment, easy to scale in the tower, which brings great inconvenience to operation, high investment cost, and requires CO 2 The content is high (above 95%), otherwise ammonia loss is serious, when CO 2 The content is 90% to 95%, and the loss of ammonia is about 10% to 15%. When CO 2 When the content is about 80%, the loss rate of ammonia is greater than 20%, and recycling the lost ammonia will greatly increase the operating cost

Images